The slope of the perpendicular line of y=5x would be -1/5, since slopes are always opposite reciprocals when they are perpendicular to each other.
So, to set up your equation is the hardest part. If you remember the basic format, you're set.
I(t) = P * (1+r%)^t
t= time and this will be our variable
Initial amount P = $2740
Rate = 4.3% which converts numerically into .043
I(t) = 7000
Before we get to find out how to find how many years it takes to get to $7000, set up the basic equation by plugging in what we know.
I(t) = $2740(1+4.3%)^t
I(t)=2740(1.043)^t
Now plug in for $7000 for I(t)
7000=2740(1.043)^t Divide both sides by 2740
7000/2740 = 2740/2740(1.043)^t
2.55474453=(1.043)^t
Now you can solve for t in two ways. You can either use the natural log or graph it on your graphing calculate and see when the two equations meet.
In your calculator you can set up:
ln(2.55474453)/ln(1.043) = t which is the method I prefer since it's much simpler
t=22.278528
but you can also graph it in your ti-84
with
y1=2.55474453
y2=(1.043)^x
and find where they intersect on the graph.
either way it'll be the same answer
List the degrees from least to greatest ie, 11,7,7,6,4,3 then the first is ur degree. So the answer is D. 11
